<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
    <style>
        .box{
            width: 500px;
            height: 500px;
            border: 30px solid rgba(0,0,255,0.3);
            padding:30px;

            background:url(images/baby0.jpg) no-repeat;
            background-size: cover;

            /* 背景原点  控制背景从什么地方开始显示*/
            /*(默认值)*/
            /*background-origin: padding-box;*/
            /*从border-box开始显示*/
            /*background-origin: border-box;*/
            /*从content-box开始显示*/
            background-origin: content-box;

        /*(默认值)*/
        }
    </style>
</head>
<body>
    <div class="box">

    </div>
</body>
</html>